The determination of the live weight of farm and ranch animals is an important aspect of their health maintenance as well as in the successful conduct of many modern agricultural enterprises. That task, however, is not simple or easy to accomplish. For instance, most ranch animals are large and not particularly easy to manage in confined spaces. Scales robust enough to accommodate an individual livestock animal are expensive and not very portable in use. As a consequence, it is rare that individual animals actually are weighed.
The problems mentioned above have resulted in the development of several different “weighing aids”, such as tables of pertinent values and tape measures that incorporate such tables. For example, tables of correspondences between chest girth of cattle and their live weight have been published. These approaches have been incorporated into Tyvek® or cloth tapes for measuring chest girth and these hand-held aids can be purchased and have been widely used.
Even with the availability of such tapes and tables, this indirect weight determination of an animal, such as a dairy or beef cow, is usually a difficult activity and not performed very often. For instance, the person weighing the animal must wedge him or herself between animals in a stanchion barn and risks injury when attempting to take a measurement. Also, these previous approaches increase both the time involved and the level of inconvenience, requiring accurate manual measuring and transcription of data by hand.
Some previous systems incorporated a laser rangefinder under controlled conditions that was used to correlate several linear dimensional measurements of livestock with their live weight. However, the elaborate equipment and controlled conditions preclude their use as an everyday tool on a farm or ranch.
Nevertheless, in modern agricultural operations (e.g., large dairy or beef cattle ranches or feedlots) there is a desire to determine live weight as compared to previous eras, with the increased use of antibiotics and the potential for residual drugs in carcasses. Increasingly, such large enterprises operate with automated recordkeeping for efficiency and to help maintain healthy animals. Livestock may be tagged or implanted with bar codes or Radio Frequency Identifier Devices (RFID) for automated wireless data entry into databases that provide an improved level of detailed record-keeping and the ability to track each animal from birth onwards, as well as storing information on the entire herd.
Live weight is also an implicit factor in determining the Body Condition Score (BCS) for cattle. This ranking system, which helps to identify problem cows, has not explicitly incorporated weight trends into its animal histories, largely because they have not been readily available. Because BCS has become integrated into ranch management systems, individual weight histories will become more common and useful if they are easily available.
In addition, both State and Federal Departments of Agriculture and Health are increasingly concerned about food safety and environmental impacts. These agencies exercise supervision by establishing standards and regulations for the environments in which these animals live. Not only can a record of weights contribute to an animal's health over a period of years, but it is an important factor in determining the appropriate dosage of medication at various stages in the animal's life. Pharmaceutical manufacturers typically recommend dosing pharmaceuticals based on an animal's weight. An accurate dosage based on weight leads to more effective treatment. Under-dosing or over-dosing an animal can cause side effects, may not improve the animal's health, and can lead to residues of pharmaceuticals, such as antibiotics, in the animal's milk or at slaughter.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and/or relative positioning of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. It will further be appreciated that certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required. It will also be understood that the terms and expressions used herein have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study except where specific meanings have otherwise been set forth herein.